Bottom portion housing for a mobile device



FIG. 1 is a first side view of an ornamental design of an embodiment of a bottom portion housing for a mobile device showing our new design;

FIG. 2 is a second side view thereof;

FIG. 3 is a third view thereof;

FIG. 4 is a foruth view thereof;

FIG. 5 is a fifth side view thereof;

FIG. 6 is a sixth side view thereof; and,

FIG. 7 is an isometric view thereof.

The broken lines shown in FIGS. 1-7 are included for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a bottom portion housing for a mobile device, as shown and described. 